External stone services

Stone selection

​Our Chartered Geologists are able to carry out an initial review of stone types under consideration by the client and if required, suggest suitable alternatives. This review will take into account the technical properties of the stone, any precedent and its location on the building with regards to weathering and staining. In reviewing the stone types under consideration we can also provide general information with regards to availability, relative costs and potential suppliers.

Quarry and fabrication works visits

We are highly experienced and have visited dimension stone quarries around the world including North and South America, Northern and Southern Africa, East Asia, India and most countries in Europe. We can co-ordinate and take part in visits to suppliers / quarries to help a project team get a better understanding of the visual and technical characteristics of the stone under consideration. Our wide experience helps the team gain a better understanding of the visual and technical characteristics of any stone under consideration as well as availability and constraints on extraction. We will comment on available block sizes and quality which directly influence the size of pieces for use on a project and help the team understand the most economic use of the material. We are familiar with various types of fabrication works and machinery and can comment on their suitability for use in the various forms of production.

Visual range selection

​Natural stone can be an inherently variable material sometimes with a wide range of visual characteristics. We believe that understanding the visual characteristics of any stone is an important part of a project as there needs to be a common agreement between the client, architect, sub-contractor and supplier on what is possible within given programme and cost constraints. The level of information gained from these visits often helps a project team provide tenderers with specific information on the visual requirements of a stone type. This detail can help a tenderer obtain more accurate pricing for the required stone type..

Design and specification

Our team, along with our structural and façade engineers can explain and discuss the technical merits of different forms of stone construction (e.g. hand-fixed, rainscreen, stone faced precast etc.) that may be appropriate to the project. We can review and comment on Architect’s or sub-contractor’s details, e.g. stone sizes and thickness, methods of fixing, size and location of movement joints for various construction types using stone, such as external cladding, internal lining, paving and flooring. We can provide a project specific performance based specification for stone cladding, internal lining and flooring and external paving. Our specifications do not need to be restricted to the stone itself and can include clauses associated with the preferred fixing methods ( e.g. metal fixings, adhesives, composite systems etc.), the certification / testing required before and during production, mock-ups, fabrication and installation. Alternatively we can review and comment on the Architect’s specification.

Testing

As part of our specification we will review any existing test data for the stone and comment on its suitability. This will include reference to any CE Certification and Declaration of Performance data. In the absence of any recent test data we will design a bespoke testing programme, undertake sampling (if required) and arrange for the necessary testing to be carried out. Following the completion of any testing we can provide an interpretative report outlining the acceptability of the stone on the basis of the test results obtained. Frequently testing of stone is over-specified and there are normally savings to be made by rationalising the test requirements. This relies on an understanding of the materials, historical test data and its intended use on the project. Occasionally we may need to design non-standard test programmes which we usually do in conjunction with selected UKAS accredited test laboratories.